Brown does an excellent job exposing the artistic life of the painter. The biography focuses on the art itself, and equally on Velazquez' relationships with other great painters of the age. Thus the work is not only about the work of Velazquez; it explores the entire world of Spanish painting in the 17th century.
Brown writes especially about Velazquez' realism, his interest in painting plain and ordinary peopel and scenes and imbuing them with dignity, documenting their humanity respectfully and compassionately. The artist's role in the court of Philip IV is especially engaging, and it tells a lot about Spanish history at the time.
Thus The World of Velazquez is worth reading, for its intimacy with Velazquez' art and experience, its wider exploration of Spanish art in the 17th century, and its treatment of general (especially political) history at that time.